JPEG 2000 is the latest standard for still image coding. Instead of JPEG, with excellent coding performance and abundant features, it may become the most popular still image coding standard applying in digital cameras, digital video cameras and other digital devices.
In JPEG 2000, however, embedded block coding is the most complicated part as well as a hot topic investigated by researchers. Conventional coding schemes process code-block bit-plane by bit-plane in serial, and have many drawbacks listed as follows:
1. The processing rate is slow.
2. The requirement of on-chip random access memory is high.
3. The efficiency and integration of the system is poor, because it accesses off-chip memory by bit-plane as a unit.
The present invention has solved the above problems with parallel coding technique. It speeds up the processing rate and avoids the requirement of memory for state variables. Furthermore, it greatly improves the access scheme of external memory and facilitates integration of the coder by dealing with a discrete wavelet transform (DWT) coefficient at word-level in each time.